The present invention relates to carts and more particularly to wheeled or castered hand carts, hamper tracks, and the like for various applications such as carrying packages, waste, hospital and laundry items, etc.
Prior art carts of the type described include U.S. Pats. Nos. 2,726,095 to Emery and U.S. Pat. No. 4,684,087 to Spickard. These carts include a base frame mounted on casters or wheels and side and top elements to confine the cart interior. U.S. Pat. No. 3,806,146 to Shawe discloses a disposal bag holder with a base having caster mounting plates mounted at the four comers of the base and an upper frame which holds the bag within a number of confining rods extending to the base. Each rod has a base portion that forms an L-shaped configuration with a horizontal end or shank that fits into strap seats that clamp the L-shaped rods to the base.
Also, Royal Basket Trucks, Inc., Darien, Wis., publicly introduced in about 1982 a cart that includes a base frame mounted on casters, which frame comprises cross members for increasing the rigidity and strength. An upper frame having side and end sections forming a ring holds the upper part of a vinyl or canvas bag or liner resting in the interior of the cart. A plurality of resilient, metal rods depend from the ring frame and have their lower ends or base portions terminating in step-shaped configurations facing toward the interior of the ring. The base assembly includes a rectangular peripheral members with apertures so that the peripheral members engage and support the horizontal portions of the step-shaped base configurations and the apertures of the peripheral member horizontal top surface receives or engages the ends or bottoms of the base portions of the rods.
U.S. Pat. 4,915,329 to Doninger discloses a similar cart designed to be quickly disassembled by providing upper metal tubular frame parts detachably held together by releasable saddle screws and nuts and a metal L-shaped peripheral base frame having a vertical part to receive and support the horizontal part of the step-shaped rod base and a horizontal ledge to engage the end or free vertical part of the step-shaped rod base.
Although these carts are functional, there is still a need in the art for improved carts having better strength and endurance characteristics and that can be manufactured efficiently for less costs. For example, the wooden bases of the ROYAL carts tend to weaken with constant pounding and loosen at their joints. The metal bases of the DONINGER cart are also weak for many applications and require too many base welds due to their L-shaped design. Also, the detachable screws at the upper frame tend to loosen with changes in temperature and time causing too much stress on the rods/upper frame welds which result in weld tears, cracks or breaks.